Don't bother replacing the springs. Instead, buy and install the Carefree of Colorado Pioneer upgrade Kit
. It eliminates the springs (and their problems of rusting and breaking) and uses a simple, worm-drive, crank system to open/close the awning. Honest, once you convert to it, you'll keep asking yourself why Carefree never used this system originally. The worm-drive allows you to really tighten the awning against the side of the coach and IT WILL NOT UNROLL- even if you forget to close the plastic locks on the arms.
The instructions recommend two people to install the kit, but with a little "Yankee ingenuity" I was able to install it myself. You don't have to remove the awning, but it has to be fully extended. You do have to be aware that there two springs in the awning tube and while one is "dead" (broken), the other is as live as a rattlesnake waiting to strike so be extra careful and alert when you do that side.
As an added bonus, the kit eliminates that ornery locking mechanism used to set the awning to roll/unroll (or lock/unlock). This was always a PIA to move on my awning.